In the production of magazines, a cover is typically secured to a book block after the signatures have been gathered. For example, the cover can be fed by a cover feeder and either stitched (e.g., stapled) to the book block on a saddle stitcher or glued to the book block on a perfect binder. In either situation, it is cosmetically important to align (i.e., "register") the center of the cover with the binding of the book block prior to the securing step. This is particularly true when the cover has a printed demarkation representing the binding of the magazine. For example, a perfect bound magazine may have the magazine title or the publication date printed on the binding. Without proper registration of the cover to the book block; the printed demarkation will not be positioned on the binding, thereby resulting in a defective product.
Traditionally, registration of the cover to the book block was performed manually by the operator of the binding machine. That is, the operator removed a bound magazine after the cover has been secured, and visually inspected the registration of the printed demarkation with the binding of the book block. If misregistration was detected, the cover feeder would be adjusted by manually moving guide rails in a lateral direction relative to the book block holder. After adjustment, another bound magazine was removed and inspected. This process continued until proper registration was achieved.
The traditional process has some disadvantages. First, since magazines that are removed from the process are difficult to reintroduce beck into the process, the removed magazines are typically discarded, resulting in wasted product, or repaired, resulting in decreased efficiency. In addition, if misregistration was substantial, all products having the misregistration must be discarded. Further, current production rates do not allow each cover to be manually inspected for registration, thereby potentially resulting in defective products being shipped. Also, since the inspection takes place after the cover has been attached to the book block, the resulting defective magazine must be discarded.
The above-noted problems are exacerbated when a cover wrap is applied to a magazine. A cover wrap is used to protect the exterior surface of a magazine cover. The cover wrap is applied to the outside surface of a cover prior to securing the cover to the book block. To inspect the resulting magazine for proper cover registration, the cover wrap must be removed from the cover. Such removal of the cover wrap results in a defective magazine that must be discarded, even if the cover is properly aligned.